[JRTJH]

If the tires will fit the wheel wells (or the trailer modified so they fit), if the tires are rated to carry the weight of the trailer and if the wheels are wide enough for the tire mounting recommendations, then they would probably work.

If you're looking to do something like these photos, then realize that Keystone (and almost all other manufactured travel trailers) simply don't have the structural rigidity or strength to be towed like these trailers. Trying to do so would probably mean that your trailer becomes a "one season toy". They aren't engineered or designed to be subjected to this kind of use and probably would "self destruct" if subjected to this kind of use...